Storage can be made available to virtual machines in a number of
different ways. This chapter covers some possible configurations.
The most straightforward method is to export a physical block device (a
hard drive or partition) from dom0 directly to the guest domain as a
virtual block device (VBD).
Storage may also be exported from a filesystem image or a partitioned
filesystem image as a file-backed VBD.
Finally, standard network storage protocols such as NBD, iSCSI, NFS,
etc., can be used to provide storage to virtual machines.